A few months ago I replaced the bottom bracket on my 2002 Fuji Finest. After reassembly I noticed the chain "wobbles" slightly when pedaling. You can see in this video the chain drifts toward the outer edge of the derailleur during rotation.
I assumed the issue is caused by one of two things: 1) the BB; 2) the crank.
Here is what I've attempted so far:
I had another, new BB available. Thought maybe Bracket A was wonky. Both are Shimano square taper brackets new out of the box. I replaced bracket A with bracket B, reattached the arm. Still wobbles.
I had a spare, new crankset available out of the box. Thought maybe Crank A was bent. I tried Cranks A and B on both brackets A and B (so combinations of AA AB BB BA). Still wobbles.
I reseated both cranks on the BBs. The bolts are on tight and the crank itself feels solid. Still wobbles.
At this point I'm a bit stymied. I accept that the bike is rather old, and the bike still functions just fine (I've put a few hundred miles on it since the BB replacement). My main concern is the wobble may get worse if not addressed now.
Any thoughts on this? I appreciate the insight of the more technically adept!